===================================================================
RCS file: /cvs/funnyos/kern/kern_sched.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- funnyos/kern/kern_sched.c	2007/11/19 15:54:33	1.1
+++ funnyos/kern/kern_sched.c	2007/11/20 16:07:24	1.2
@@ -1,9 +1,131 @@
 /*
- * $Id: kern_sched.c,v 1.1 2007/11/19 15:54:33 nbrk Exp $
+ * $Id: kern_sched.c,v 1.2 2007/11/20 16:07:24 nbrk Exp $
  */
 #include <sys/types.h>
 #include <sys/kern_sched.h>
+#include <sys/kern_time.h> /* for HZ */
+#include <sys/mem.h>
 
 #include <libkern/printf.h>
 
+
+/* config.c gives us tasks that we'll schedule */
+extern struct u_task config_tasklist[];
+
+/* list of k_tasks */
+struct k_task *ktasklist;
+
+/* pcb of running task; we will save context there when enter irq_mode */
+uint32_t *curpcb;
+
+/* total tasks; used to TID generation */
+uint8_t ntasks;
+
+/* "idle" task exists forever and occupy cpu when there is no other task pretending. */
+const struct u_task idle_utask = {"idle", 0, NULL};
+
+
+void
+sched_init(void)
+{
+	/*
+	 * Create struct k_task for each u_task that user described in config_tasklist.
+	 */
+	struct u_task *utaskp;
+	struct k_task *ktaskp, *oldktaskp;
+
+	ntasks = 0;
+
+	/*
+	 * Create an "idle" task which always has TID 0.
+	 */
+	ktaskp = kmalloc(sizeof(struct k_task));
+
+	if (ktaskp == NULL)
+		panic("can't allocate memory for idle task\n");
+
+	/* link u_task for idle task */
+	ktaskp->kt_utask = (struct u_task *)&idle_utask;
+
+	/* TID (always 0) */
+	ktaskp->kt_tid = 0;
+
+	/* idle task is always in state READY (or RUNNING, if on processor now) */
+	ktaskp->kt_state = TASK_READY;
+
+	/* next task in list isn't up yet (and prev too) */
+	ktaskp->kt_next = NULL;
+
+	/* make "idle" task first task in ktasklist, system k_task list */
+	ktasklist = ktaskp;
+
+	/* bump ntasks to 1 */
+	ntasks = 1;
+
+	/* preserve pointer to this k_task so we can link-in next task */
+	oldktaskp = ktaskp;
+
+	/*
+	 * Idle task set up completed.
+	 * Configure all other system tasks,
+	 */
+
+	/* look through tasklist */
+	utaskp = config_tasklist;
+	while(utaskp->ut_name != NULL) {
+
+		/* try to allocate memory for ktask */
+		ktaskp = kmalloc(sizeof(struct k_task));
+
+		if (ktaskp == NULL)
+			panic("can't allocate memory for task '%s'\n", utaskp->ut_name);
+
+		/*
+		 * Successfully allocated new ktask.
+		 */
+
+		/* link u_task */
+		ktaskp->kt_utask = utaskp;
+
+		/* set TID (Task Identificator) */
+		ktaskp->kt_tid = oldktaskp->kt_tid + 1;
+
+		/* state */
+		ktaskp->kt_state = TASK_READY;
+
+		/* link current task in previous task's structure */
+		oldktaskp->kt_next = ktaskp;
+
+		/* NULLify kt_next of current task */
+		ktaskp->kt_next = NULL;
+
+		/* save current ktask for use with next ktask */
+		oldktaskp = ktaskp;
+
+		/* bump ntasks */
+		ntasks++;
+
+		/* shift to next element in config_tasklist[] */
+		utaskp++;
+	}
+
+	/* make this list circularly linked (e.g point list's last->next node into first) */
+	ktaskp->kt_next = ktasklist;
+
+	printf("kern_sched: created %d tasks:", ntasks);
+
+	/* print tasks' names */
+	ktaskp = ktasklist + 1; /* skip (first) "idle" task (display it as the end of circularly list) */
+	do {
+		printf(" %s", ktaskp->kt_utask->ut_name);
+
+		if (ktaskp->kt_tid == NULL) /* that was an "idle" task */
+			break;
+
+		ktaskp = ktaskp->kt_next;
+	} while(1);
+
+	printf("; HZ=%d\n", HZ);
+
+}